If you a keen follower of the NBA and the NHL Playoffs, then the Betting Zig-Zag Theory is a term that you have probably come across at some point in your sportsbook endeavors. The online betting theory has particularly been popularized over the past decade or so, with the NBA and NHL best-of-seven playoff series—which uses the 2-2-1-1-1 playing format—being the driving force for its proponents.